JP2001145025A - Solid-state image pickup device and its drive method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid-state image pickup device and its drive method that can output an image without deteriorating S/N and decreasing the sensitivity even in a high speed read mode, without deteriorating the resolution in the vertical direction, a complicated drive mode and the need for a special circuit configuration. SOLUTION: The solid-state image pickup device is provided with photodiodes 18 arranged in the longitudinal direction, a vertical CCD 19 that reads signal charges that are photoelectric-converted by the photodiodes 18 and transfers the charges in the longitudinal direction, a vertical transfer electrode 22 to which a drive pulse to drive the vertical CCD 19 is applied, a horizontal CCD 20 that transfers the signal charges from the vertical CCD 19 laterally and outputs them externally, and a transfer drive means that outputs an image signal with different combinations to be added by each field, where one frame consists of a plurality of fields in each of which signal charges are interleaved longitudinally, the interleaved charges are read, summed and transferred.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state imaging device and a driving method thereof, and more particularly, to a solid-state imaging device which performs charge transfer corresponding to interlaced scanning and a driving method thereof.

[0002]

2. Description of the Related Art Conventionally, there has been known a digital camera (solid-state imaging device) that can convert an optical image into an electric signal and output it to obtain an imaged screen. This digital camera is a C-type digital camera that performs charge transfer corresponding to interlaced scanning.
CD (charge coupled device)
When a moving image such as a view finder is projected, the CCD image sensor is driven by pixel thinning in order to support a high frame rate.

FIG. 7 is an explanatory view showing an example of reading out a conventional CCD image sensor. As shown in FIG.
The D image sensor 1 includes a photodiode (photodiode: PD) 2 as a photoelectric conversion element, a vertical CCD
3 and a horizontal CCD 4. The bit numbers 1 to 7 indicate that the photodiode 2 closest to the horizontal CCD 4 is 1
The bit indicates the number when counted in the vertical direction.

The photodiodes 2 are arranged two-dimensionally in the vertical and horizontal directions (only one column is shown), and in each column, the vertical CCDs 3 are juxtaposed for each individual column (only one column is shown). Each vertical CCD 3 arranged in tandem is
Is connected to one horizontal CCD 4 arranged in a row at the lower end of the horizontal CCD. In each of the vertical CCDs 3, the vertical transfer electrodes 5 are vertically arranged at a ratio of two to one of the photodiodes 2, and in each of the horizontal CCDs 4, the horizontal transfer electrodes 6 are horizontally arranged for each of the vertical CCDs (one each). Only shown).

[0005] Each photodiode 2 individually converts the amount of incident light into signal charges and accumulates them. One of the vertical transfer electrodes 5 also serves as a read electrode for reading out charges from the photodiode 2 to the vertical CCD 3.
Then, for example, by applying a 10-phase drive pulse, readout by vertical 10-phase drive is performed.

When signal charges are read out by thinning using the CCD image sensor 1, only one pixel out of five pixel lines is read out. First, a negative potential is applied to the electrode to which the drive pulse ΦV1 is applied,
A potential barrier a where no charge is stored is formed. By forming the potential barrier a, the upper and lower charges are prevented from being mixed, and then a high positive potential is applied only to the electrode to which the drive pulse ΦV6 is applied, and the signal charges b of the second and seventh bits of the photodiode 2 are changed. Read to vertical CCD3.

Thereafter, the read signal charges b are sequentially transferred in the vertical CCD 3 in the direction of the horizontal CCD 4 (from top to bottom in the figure), and are transferred to the horizontal CCD 4 after reaching the bottom, although the transfer method is not shown. Thereafter, the signals are sequentially transferred in the horizontal CCD 4 and output as image signals from a charge detection unit (not shown).

As a result, since one pixel is read out every five pixel lines, the pixels are thinned out to 1/5 in the vertical direction, and the frame rate is increased while driving the horizontal CCD 4 at the same frequency as the normal reading operation. Increases about five-fold.

Further, as a method related to a conventional method of driving a CCD image sensor which performs charge transfer corresponding to interlaced scanning, there is known a method of driving a solid-state image pickup device disclosed in Japanese Patent Application Laid-Open No. 8-149374. Have been.

In the case of this driving method of the solid-state image pickup device, in the previous field, the charges of the pixels in the three columns adjacent in the vertical direction are added together and read out, and the charges are not read out between the set of the three columns added together. In the next field, in the next field, the charges of the three rows of pixels centered on the rows of pixels that were not read out in the previous field are added together and read out, and among the three rows read out in the previous field, The interlaced scanning is performed by preventing the pixels in the center column from being read.

Thus, the center pixel of the three pixels is
Since the accumulation time is doubled with respect to the other two adjacent pixels, the sensitivity becomes twice as high, and an intermediate characteristic between the field accumulation reading and the frame accumulation reading can be exhibited.

[0012]

However, in reading out signal charges by the above-described conventional thinning-out,
The number of pixel lines read from the photodiode 2 is 1/5
Therefore, in the high-speed read mode, the output signal charges are reduced to 1/5.

Therefore, in the high-speed readout mode, the sensitivity is reduced to about 1/5 of that in the normal operation readout mode, so that only an image having a low sensitivity and a deteriorated S / N can be obtained. Further, the resolution in the vertical direction was extremely deteriorated, that is, about 1/5 of that in the normal read mode. This is because, in the high-speed read mode, since the photodiode 2 to be read is ５, the output sensitivity and resolution are both about ５.

In the conventional method of driving a solid-state image pickup device, the driving mode becomes complicated, and it is necessary to reduce the converted signal once fetched into a memory or the like. I need.

An object of the present invention is to output an image in which the sensitivity is not lowered and the S / N is not deteriorated even in the high-speed read mode, and the resolution in the vertical direction is not deteriorated. To provide a solid-state imaging device and a driving method thereof that do not require complicated circuit configuration and do not require a special circuit configuration.

[0016]

In order to achieve the above object, a solid-state imaging device according to the present invention reads a plurality of photoelectric conversion elements arranged in a vertical direction, and reads signal charges photoelectrically converted by the photoelectric conversion elements. Vertical CCD for vertical transfer
A vertical transfer electrode to which a drive pulse for driving the vertical CCD is applied; and a horizontal CCD for transferring signal charges from the vertical CCD in the horizontal direction and outputting the signal charges to the outside, and thinning out the signal charges in the vertical direction. One frame is composed of a plurality of fields that are read, added, and transferred, and a transfer driving unit that outputs image signals having different combinations of additions for each field is provided.

With the above arrangement, the transfer driving means forms one frame by a plurality of fields in which signal charges are thinned out in the vertical direction, read out, added, and transferred, and the combination to be added is different for each field. Output a signal. As a result, even in the high-speed read mode, it is possible to output an image in which the sensitivity is not lowered and the S / N is not deteriorated, the resolution in the vertical direction is not deteriorated, and the drive mode is not complicated,
No special circuit configuration is required.

Further, the solid-state imaging device can be driven by the method for driving a solid-state imaging device according to the present invention.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a solid-state imaging device according to an embodiment of the present invention. As shown in FIG. 1, the solid-state imaging device 10 includes a circuit board 11, a vertical drive circuit 12, a horizontal drive circuit 13, a drive control circuit 14, a signal processing circuit 15, an inversion circuit 16, and a color signal processing circuit 1.
7.

The solid-state imaging device 10 has a CCD image sensor (solid-state imaging device) for performing interline transfer corresponding to interlaced (interlaced) scanning, and is used for a portable digital camera or the like. Many of these digital cameras have a viewfinder,
The shooting target can be displayed as a moving image on the viewfinder. The CCD image sensor is built on a circuit board 11, and a vertical drive circuit 1
2 and the horizontal drive circuit 13 are connected.

The drive control circuit 14 comprises a so-called microcomputer and has a CPU (central process).
ssing unit), RAM (random ac)
cess memory), ROM (read only)
y memory) is provided as hardware. A predetermined control program is mounted in the drive control circuit 14 in advance, and the drive control circuits 14 and 13, the signal processing circuit 15, and the inversion circuit 1 correspond to the control program.
6 and the operation of the color signal processing circuit 17 are controlled.

The vertical drive circuit 12 and the horizontal drive circuit 1
3 and a drive control circuit comprising a drive control circuit 14,
A plurality of fields are provided in which pixels are thinned out in the vertical direction of a pixel line composed of a plurality of photoelectric conversion elements arranged in the vertical direction, read out, added, and transferred, and one frame is composed of the plurality of fields, and the addition is performed for each field. Each combination outputs a different image signal.

FIG. 2 is a block diagram showing the configuration of the circuit board of FIG. As shown in FIG. 2, the circuit board 11 includes
Photodiodes (photons) that are a plurality of photoelectric conversion elements
The first CCD 18, a plurality of vertical CCDs 19, a plurality of horizontal CCDs 20, and an output unit (charge detection unit) 21 are formed as an integrated circuit.

The plurality of photodiodes 18 are arranged two-dimensionally in the vertical and horizontal directions, and a vertical CCD 19 is arranged in each column (pixel line) for each column. Each of the vertical CCDs 19 arranged in a column is connected to one horizontal CCD 20 arranged in a row at the lower end of each vertical CCD 19. In each of the vertical CCDs 19, the vertical transfer electrodes 22 are vertically arranged at a ratio of two to one of the photodiodes 18.

Each photodiode 18 converts the amount of incident light into individual signal charges and accumulates them. The accumulated signal charges are read out from each photodiode 18 to a vertical CCD 19 and sequentially transferred in the vertical direction. Are transferred from the vertical CCD 19 to the horizontal CCD 20, and further sequentially transferred in the horizontal direction, and output from the output unit 21 to the outside.

FIG. 3 is an explanatory diagram showing an example of reading and adding for each field according to the present invention. This example
In the vertical 10-phase driving method, a case of a 2-field 1-frame configuration is shown.

In FIG. 3, each bit of 1 to 7 indicates a photodiode 18, and each bit number indicates that the photodiode 18 closest to the horizontal CCD 20 is 1 bit.
And the numbers when counted in the vertical direction are shown. The even-numbered vertical transfer electrodes 22 also serve as readout electrodes, and are configured to perform independent readout by setting a mode.

In the first field, first, a low-level voltage is applied to the vertical transfer electrode 22 to which the vertical drive pulse ΦV1 is applied to form a potential barrier a. The formation of the potential barrier a prevents mixing of signal charges located above and below the potential barrier a. The vertical transfer electrode 22 to which the vertical drive pulse ΦVn is applied is hereinafter abbreviated as an electrode ΦVn.

Next, the electrodes ΦV2, ΦV6, ΦV10 are
Electrodes ΦV3, ΦV4, ΦV5, ΦV7, ΦV8, ΦV9
The signal charge b is read out from the photodiode 18 to the vertical CCD 19 by applying a high-level voltage higher than the middle-level voltage applied to the vertical CCD 19. After reading,
The signal charges b read in the vertical CCD 19 are added.

Thereafter, the added signal charges c are transferred to the horizontal CCD 19 in the vertical CCD 19, although the transfer method is not shown.
The data is sequentially transferred in the direction (from top to bottom in the figure), reaches the bottom, and is transferred to the horizontal CCD 20. FIG. 3 shows one horizontal transfer electrode 23 to which the horizontal drive pulse ΦH1 is applied.
Only shown. After being read out by the horizontal CCD 20, the signal charges c are further transferred in the horizontal CCD 20 in the direction of the output section (from right to left in FIG.
Are output as image signals.

That is, by adding the signal charges b in the vertical CCD 19, the signal charges c sequentially transferred in the vertical CCD 19 become three electrodes ΦV2, ΦV6, Φ
It has three times the charge amount (b × 3) of each signal charge b read from V10.

In the second field, first, the electrode Φ
A low level voltage is applied to V9 to form a potential barrier a. Next, the electrodes ΦV4, ΦV8, ΦV10
And electrodes ΦV1, ΦV2, ΦV3, ΦV5, ΦV6, Φ
A high-level voltage higher than the middle-level voltage applied to V 7 is applied, and the signal charge b is read out from the photodiode 18 to the vertical CCD 19. After reading, the signal charges b read in the vertical CCD 19 are added.

Thereafter, the added signal charges c (c = b ×
3) are sequentially transferred in the vertical CCD 19, and
The data is sequentially transferred in the horizontal CCD 20 and output from the output unit 21 as an image signal.

Therefore, by the above-described reading and addition, signal charges for five pixels are transferred in the vertical direction during one horizontal blanking period, so that an image which is thinned out to 1/5 vertically can be output. In addition, reading in the pixel line
Since three of the five pixels are used, three times the sensitivity can be obtained as compared with reading of only one pixel. Further, in the second field, three different combinations of pixels including the remaining pixels not read out in the first field are read out. Therefore, compared to the case where the same combination of pixels is read out and added in all fields, the resolution is almost twice as high. Obtainable.

This is because reading of signal charges from the photodiode 18 has a plurality of combinations that are periodically arranged in the vertical direction, and the same reading is performed between pixels of the same combination.
This is because a contrivance is made so that independent reading can be performed on signal charges for five pixels that are consecutive in the vertical direction so that independent reading is performed between pixels of different combinations.

As described above, the solid-state imaging device 10 shown in FIG.
, The drive control circuit 14 includes both drive circuits 12 and 13 as interlace means and thinning-out read control means.
, The interlace operation and the thinning-out read operation are selectively executed. However, in the solid-state imaging device 10, as described above, the drive control circuit 1
Since the reference numeral 4 also functions as a charge adding means, the signal charges of the plurality of photodiodes 18 positioned at a predetermined period in the vertical direction are added when performing the thinning-out reading operation.

More specifically, the drive control circuit 14
Is that the signal charges b of the plurality of photodiodes 18 are read out to the vertical CCD 19 at mutually different timings by controlling the operation of the vertical drive circuit 12 to apply a voltage to the vertical transfer electrodes 21, and the readout is performed at the preceding stage. The output signal charges b are transferred in the vertical direction of the vertical CCD 19 before the subsequent signal charges b are read. In the course of this transfer, the signal charges b read from the plurality of photodiodes 18
Are added and synthesized into one by the vertical CCD 19.

Further, the signal charge c read out and added and synthesized is detected by the output section 21 as a detection circuit, and then, in the signal processing circuit 15, sampling, gain and γ correction, and A / D (analog to digital) are performed. 2.) Signal processing such as conversion is performed. After signal processing, inverting circuit 1
In 6, it is determined whether or not the signal charges in the vertical direction are reversed before and after the processing so that the processed signal becomes the same as the pixel arrangement of the previous field. The decision of whether to flip or not is
This is performed by the control operation of the drive control circuit 14. afterwards,
In the color signal processing circuit 17, R (red), G
(Green) and B (blue) are processed as color signals corresponding to the three primary color lights.

Therefore, in the above-described configuration, the solid-state imaging device 10 can also convert a two-dimensional optical image into a serial electric signal similarly to the solid-state imaging device (digital camera) shown in the conventional example. The interlaced operation and the thinned-out read operation can be performed using the converted electric signal.

FIG. 4 is an explanatory diagram showing another example of reading and adding for each field according to the present invention. In the case of this example, what is read out and added in the second field is the signal charges for two of the five pixels. Other configurations and operations are the same as those shown in FIG.

As shown in FIG. 4, in the first field, first, a low-level voltage is applied to the electrode ΦV1 to form a potential barrier a. Next, the electrode ΦV
2, ΦV6, ΦV10, electrodes ΦV3, ΦV4, ΦV
5, a high level voltage higher than the middle level voltage applied to ΦV7, ΦV8, ΦV9,
The signal charge b is transferred from the photodiode 18 to the vertical CCD 19
Read out. After reading, the three read signal charges b are added in the vertical CCD 19.

Thereafter, the signal charge c after addition (c = b ×
3) are sequentially transferred in the vertical CCD 19, and
The data is sequentially transferred in the horizontal CCD 20 and output from the output unit 21 as an image signal.

In the second field, first, the electrode Φ
A low-level voltage is applied to V1 to form a potential barrier a. Next, the electrodes ΦV4 and ΦV8 are
V1, ΦV2, ΦV3, ΦV5, ΦV6, ΦV7, ΦV
9, a high-level voltage higher than the middle-level voltage applied to ΦV10 is applied, and the signal charge b is read out from the photodiode 18 to the vertical CCD 19. After the reading, the two read signal charges b are added in the vertical CCD 19.

Thereafter, the signal charge d after addition (d = b ×
2) are sequentially transferred in the vertical CCD 19, and
The data is sequentially transferred in the horizontal CCD 20 and output from the output unit 21 as an image signal.

Therefore, by the above-described reading and addition, signal charges for five pixels are transferred in the vertical direction during one horizontal blanking period, so that an image which is thinned out to 1/5 vertically can be output. In addition, reading in the pixel line
In the first field, three out of five pixels are used, and in the second field, two out of five pixels are used. Therefore, at least twice the sensitivity can be obtained as compared with reading out only one pixel. Further, in the second field, since pixels of different combinations including the remaining pixels not read in the first field are read, the resolution is almost twice as high as in the case of reading and adding the same combination of pixels in all fields. Obtainable.

Further, as compared with the case shown in FIG. 3, since the potential barrier a does not move and the first and second fields can be in the same transfer mode, the operation of the drive pulse of the vertical CCD 19 is not complicated. The circuit scale and the driving circuit can be further simplified.

FIG. 5 is an explanatory diagram showing still another example of reading and adding for each field according to the present invention. In this example, in the vertical 12-phase driving method, three fields 1
In the case of a frame configuration, reading out and adding in each of the first, second, and third fields is performed by 2 of 6 pixels.
This is the signal charge for the pixel. Other configurations and operations are the same as those shown in FIG.

As shown in FIG. 5, in the first field, first, a low-level voltage is applied to the electrode ΦV1 to form a potential barrier a. Next, the electrode ΦV
2, ΦV8, electrodes ΦV3, ΦV4, ΦV5, ΦV6,
A high-level voltage higher than the middle-level voltage applied to ΦV7, ΦV9, ΦV10, ΦV11, and ΦV12 is applied, and the signal charge b is read from the photodiode 18 to the vertical CCD 19. After reading, the vertical C
In the CD 19, the two read signal charges b are added.

Thereafter, the signal charge d after addition (d = b ×
2) are sequentially transferred in the vertical CCD 19, and
The data is sequentially transferred in the horizontal CCD 20 and output from the output unit 21 as an image signal.

In the second field, first, the electrode Φ
A low-level voltage is applied to V1 to form a potential barrier a. Next, the electrodes ΦV2, ΦV3, ΦV5, ΦV6, ΦV7, ΦV8,
A high-level voltage higher than the middle-level voltage applied to V9, ΦV11, and ΦV12 is applied, and the signal charge b is read out from the photodiode 18 to the vertical CCD 19. After the reading, the two read signal charges b are added in the vertical CCD 19.

Thereafter, the signal charge d after addition (d = b ×
2) are sequentially transferred in the vertical CCD 19, and
The data is sequentially transferred in the horizontal CCD 20 and output from the output unit 21 as an image signal.

In the third field, first, the electrode Φ
A low-level voltage is applied to V1 to form a potential barrier a. Next, the electrodes ΦV2, ΦV3, ΦV4, ΦV5, ΦV7, ΦV8,
A high-level voltage higher than the middle-level voltage applied to V9, ΦV10, and ΦV11 is applied, and the signal charge b is read out from the photodiode 18 to the vertical CCD 19. After the reading, the two read signal charges b are added in the vertical CCD 19.

Thereafter, the signal charge d after addition (d = b ×
2) are sequentially transferred in the vertical CCD 19, and
The data is sequentially transferred in the horizontal CCD 20 and output from the output unit 21 as an image signal.

Therefore, by the above-described reading and addition, the signal charges for six pixels are transferred in one horizontal blanking period in the vertical direction, so that an image thinned out to 1/6 vertically can be output. In addition, reading in the pixel line
In each of the first, second and third fields, two pixels out of six pixels are read out, so that at least twice the sensitivity can be obtained as compared with reading out only one pixel.

Further, the two fields 1 shown in FIGS.
As compared with the case of the frame configuration, the frame configuration has three fields and one frame. Therefore, the case shown in FIGS. Can be obtained that is nearly three times the resolution of

In addition, as the number of fields increases, the way of reading from the photodiode 18 can be further divided, so that the vertical CCD 19 is less likely to be saturated and a more flexible design is possible.

In each of the above embodiments, a plurality of types of color filters arranged in a predetermined arrangement for each color are mounted on individual photodiodes 18 to capture a color image. However, when a color image is captured using a color filter, the drive control circuit 14
It is desirable to add the signal charges of the plurality of photodiodes 18 to which the color filters of the same color are mounted by the above operation control.

FIG. 6 is an explanatory diagram showing an example of a color filter using the Bayer arrangement. As shown in FIG. 6, when the color filters 24 are arranged according to Bayer's proposal, that is, when the arrangement of the color filters 24 has a two-pixel cycle in the vertical direction, the same color has a two-row cycle in the vertical direction. In the thinning-out reading operation, the signal charges of the plurality of photodiodes 18 located at the cycle of the magnification of two rows may be added.

In this case, since the same color filter 24 is attached to the photodiode 18 to which the signal charges are added, signal charges of different colors are not added. That is, in each of the plurality of fields, the signal charges read out from each packet of all the vertical CCDs 19 are accumulated in the photodiodes 18 located in the same color of the color filter 24 in the signal charges of the same packet to be added. Signal charge. Therefore, the quality of the color image captured by the thinning-out reading operation can be kept good.

For example, when two fields are provided,
The information of G, B, G, B,... Is extracted from the first field, the information of B, G, B, G,. Then, after performing signal processing such as converting the charge amount into a voltage, the second
Invert the pixel array in the field.

In each of the above embodiments, the drive control circuit 14 comprising the microcomputer of the solid-state imaging device 10 operates in accordance with the software stored in the built-in ROM in advance, thereby thinning out by various functions. Various means such as a reading means and a charge adding means are logically realized. Such various means can also be formed as dedicated hardware, for example,
Appropriate software can be installed on a computer and realized, and a part can be realized by software and a part can be formed as hardware.

Further, the computer of the solid-state imaging device 10 reads a program for causing the computer to execute the above-described method of driving the solid-state imaging device 10 stored in the recording medium according to the present invention, and executes a corresponding processing operation. Can be executed. Here, the recording medium may be any hardware in which a program for causing a computer to execute various processes is stored in advance as software.
For example, a ROM or a hard disk drive (HDD) fixed to a device that includes a computer as a part.
e) a CD (compact disc) -ROM or F
D (floppy disc) and the like.

The computer according to the present invention is:
Any device that can read a program made of software and execute a corresponding processing operation may be used.
U, and ROM, RAM, I / F (in
This includes devices to which various devices such as terfaces are connected as necessary.

As described above, according to the present invention, in the solid-state imaging device 10 based on the interlaced scanning type interline transfer method in which one frame is composed of a plurality of fields, pixels are transferred from the photodiode 18 to the vertical CCD 19.
When reading, the pixels are thinned out in the vertical CCD 19 direction (vertical direction) and read.

At this time, in the first field (previous field), a plurality of pixels are read out of the thinned-out vertical pixel period, and signal charges are added and synthesized when the vertical CCD 19 is transferred to the horizontal CCD 20. Further, in the second field and the second and subsequent fields (subsequent field), a combination that has not been read in one or more of the first fields, that is, a pixel in a combination different from the first field is read, and the vertical CCD 19 Are added and combined at the time of transfer. Then, the added and combined signal charges are output as image signals. The pixel in which the signal charge is stored is read once in any one of the plurality of fields.

That is, since the pixels are thinned out in the vertical direction, the driving of the horizontal CCD 20 can increase the frame rate of the pixels while maintaining the same frequency as in the related art. In addition, by reading and adding different combinations of pixels for each field, the resolution is improved as compared with the case where the same combination of pixels is read and added in all fields.

Therefore, in order to cope with the decrease in resolution due to taking out one pixel from a plurality of pixels, the present invention increases the resolution while increasing the charge amount by using a plurality of fields, and secures a sufficient charge amount. Since high-speed readout and thinning-out scanning can be performed, for example, a digital camera that needs to capture all image information can use a viewfinder that does not need all image information to increase the speed at which the moving image to be projected can be tracked. Can be secured.

That is, if the video data is taken in early to drive the moving image, the storage time itself stored in the photodiode is reduced due to the high-speed transfer, and the charge itself is reduced. it can.

In the above-described embodiment, the number of pixels read out in the first field is not limited to two or three, but may be more. The preceding field (eg, the first field) and the subsequent field (the first field) For example, the second field)
And the read number may be different.

[0071]

As described above, according to the present invention, the transfer driving means forms one frame by a plurality of fields in which signal charges are thinned out in the vertical direction, read out, added and transferred, and each field is Since different combinations of image signals are output, it is possible to output an image in which the sensitivity is not reduced and the S / N is not deteriorated even in the high-speed readout mode, and the resolution in the vertical direction is not deteriorated. Further, the driving mode is not complicated, and no special circuit configuration is required.

Further, the solid-state imaging device can be driven by the method for driving a solid-state imaging device according to the present invention.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a solid-state imaging device according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a circuit board in FIG. 1;

FIG. 3 is an explanatory diagram showing an example of reading and adding for each field according to the present invention.

FIG. 4 is an explanatory diagram showing another example of reading and adding for each field according to the present invention.

FIG. 5 is an explanatory diagram showing still another example of reading and adding for each field according to the present invention.

FIG. 6 is an explanatory diagram illustrating an example of a color filter using a Bayer array.

FIG. 7 is an explanatory diagram showing a read example of a conventional CCD image sensor.

[Explanation of symbols]

 Reference Signs List 10 solid-state imaging device 11 circuit board 12 vertical drive circuit 13 horizontal drive circuit 14 drive control circuit 15 signal processing circuit 16 inversion circuit 17 color signal processing circuit 18 photodiode 19 vertical CCD 20 horizontal CCD 21 output section 22 vertical transfer electrode 23 horizontal transfer Electrode 24 Color filter a Potential barrier b, c, d Signal charge

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4M118 AA05 AA10 AB01 BA13 CA02 DB01 DB03 DB11 FA06 GC08 GC14 5C024 AA01 BA01 CA05 CA11 CA12 DA01 FA01 GA17 HA17 JA11 JA31 5C065 AA03 BB22 CC01 DD08 DD14 EE06 GG11 GG18 GG21GG35

Claims (16)

[Claims] 1. A plurality of photoelectric conversion elements arranged in a vertical direction,
A vertical CCD (charge cup) for reading out signal charges photoelectrically converted by the photoelectric conversion elements and transferring the read out signal charges in the vertical direction.
leading device), a vertical transfer electrode to which a driving pulse for driving the vertical CCD is applied, and the vertical CC
A horizontal CCD for transferring the signal charge from D in the horizontal direction and outputting the signal charge to the outside; forming a frame by a plurality of fields for thinning out the signal charge in the vertical direction, reading out and adding and transferring the signal charge; A solid-state imaging device comprising transfer driving means for outputting different image signals in different combinations to be added. 2. The signal charge from the photoelectric conversion element,
The solid-state imaging device according to claim 1, wherein the image is periodically read in a vertical direction. 3. The method according to claim 1, wherein the plurality of fields include a field before adding the read signal charges when reading and transferring the plurality of signal charges from a thinned vertical pixel period, and one or more previous fields. 3. The device according to claim 1, wherein when reading and transferring a plurality of the signal charges from the pixels that have not been read, the read signal charges include a subsequent field after the previous field to which the read signal charges are added. 4. Solid-state imaging device. 4. The solid-state imaging device according to claim 1, wherein the photoelectric conversion element storing the signal charge is read out in at least one of the plurality of fields. 5. The solid-state imaging device according to claim 1, wherein a color filter is mounted on the pixel. 6. In each of the plurality of fields, the signal charges read out from each packet of all the vertical CCDs are the same as the photoelectric charges positioned in the same color of the color filter in the signal charges of the same packet to be added. The solid-state imaging device according to claim 5, wherein the charge is signal charge accumulated in the conversion element. 7. The solid-state imaging device according to claim 5, wherein the color filters are arranged in a two-pixel cycle in a vertical direction. 8. A drive control circuit for controlling the operation of a vertical drive circuit and a horizontal drive circuit, and a signal processing circuit for controlling the operation of the drive control circuit, the signal processing circuit performing signal processing of the output signal charges after addition and synthesis. An inverting circuit for determining whether or not to invert and reverse the signal charge in the vertical direction so that the processed signal input from the signal processing circuit is the same as the pixel arrangement of the previous field; and input from the inverting circuit. The solid-state imaging device according to claim 1, further comprising a color signal processing circuit configured to process the converted signal as a color signal. 9. A signal charge photoelectrically converted by a plurality of photoelectric conversion elements arranged in a vertical direction is read, the read signal charge is transferred in a vertical direction by a vertical CCD, and the signal charge transferred in the vertical direction is read. In a driving method of a solid-state imaging device for transferring image signals to a horizontal direction by a horizontal CCD and outputting an image signal to the outside, a frame is constituted by a plurality of fields in which the signal charges are thinned out in a vertical direction, read, added, and transferred. A method for driving a solid-state imaging device, characterized in that different combinations of image signals are output for each field. 10. The method according to claim 9, wherein the signal charges from the photoelectric conversion element are read periodically in a vertical direction. 11. The method according to claim 11, wherein the plurality of fields include a previous field for adding the read signal charges when reading and transferring the plurality of signal charges from a thinned vertical pixel period, and one or more previous fields. 11. The device according to claim 9, wherein when reading and transferring a plurality of the signal charges from a pixel that has not been read, the signal charges include a subsequent field after the previous field to which the read signal charges are added. 12. Driving method of a solid-state imaging device. 12. A driving method for a solid-state imaging device according to claim 9, wherein said photoelectric conversion element storing said signal charge is read out in at least one of said plurality of fields. . 13. The method according to claim 9, wherein the signal charges are read out via a color filter. 14. In each of the plurality of fields, the signal charges read out from each packet of all the vertical CCDs are the same as the photoelectric charges positioned in the same color of the color filter in the signal charges of the same packet to be added. 14. The method according to claim 13, wherein the signal charges are signal charges accumulated in the conversion element. 15. The color filter according to claim 13, wherein the arrangement of the color filters has a period of two pixels in the vertical direction.
Or the driving method of the solid-state imaging device according to 14. 16. A combination in which signal charges photoelectrically converted by a plurality of photoelectric conversion elements arranged in the vertical direction are thinned out in the vertical direction, read out, added, and transferred to form one frame, and added in each field. A computer-readable recording medium storing a program for causing a computer to execute a method of driving a solid-state imaging device that outputs different image signals.